What does the dispersal pattern of identifiable fragments across hundreds of miles suggest about the Columbia breakup?

A progressive breakup that continued descending through lower, denser atmosphere

The observation that identifiable fragments were scattered across hundreds of miles indicates that the destruction of Space Shuttle Columbia was not an event confined to a single moment or altitude. The dispersal pattern is directly correlated with the velocity and altitude at which the catastrophic separation began. The wide spread suggests a progressive failure sequence, where large sections of the vehicle continued to break apart and disintegrate sequentially as the wreckage descended through the atmosphere, encountering progressively greater density and aerodynamic pressure.